The contribution of brine layers to observed reflective anisotropy of sea at 100 MHz is quantitatively assessed, and a theoretical explanation for observed reflective anisotropy is proposed in terms of anisotropic electric flux penetration into the brine layers. The sea ice is assumed to be a stratified dielectric consisting of pure ice containing ellipsoidal conducting inclusions (brine layers) uniformly aligned with their long axes perpendicular to the preferred crystallographic c axis direction. The asymmetrical geometry of the brine layers is shown to produce an anisotropy in the complex dielectric constant of sea ice. The contribution of these layers to the reflective anisotropy is examined with a numerical method of approximating the reflected power of a radar pulse incident on a slab of sea ice. Mixture dielectric permittivities are calculated for both the electric fields parallel and perpendicular to the c axis direction. These permittivities are then used to calculate power reflection coefficients at each interface in the air/sea ice/sea water system. Significant bottom reflection (R≈0.09) occurs when the polarization is parallel to the c axis. However, when the polarization is perpendicular to the c axis, the return is almost completely extinguished (R<0.003). This extinction is due primarily to absorptive loss associated with the conducting inclusions and secondarily to an impedance match at the ice/water interface that results in transmission rather than reflection of the wave.